Train-dispatching system for railroads



March 3, 1931. o. H. DICKE ET AL 1,794,591

TRAIN DISPATCHING SYSTEM FOR RAILROADS Filed April 20. 1929 5Sheets-Sheet l MW WM March 3, 1931. o. H. DICKE ET AL 1,794,591

7 TRAIN DISPATCHING SYSTEM FOR RAILROADS Filed April 20. 1929 aSheets-Sheet 2 74% W QMM m ATTORNEY March 3, 1931. o. H. DICKE ET ALTRAIN DIS PATCHING SYSTEM FOR RAILROADS Filed April 20. 1929 3Sheets-Sheet 3 Patented Mar, 3, 1931 v .U mrnn are 1? new OSCAR n. mcxnAnn NEIL n. Pnns'ron, orflnoonnsrnnf-nnw(roux,- Assxenons ToGENERAL'RAILWAYstorm]; cor/trans, censor-Insets; new YORK.

ERAIfN-DISIPATCEENG s'rsrmu ronine r nonns Application filed April so,

This "invention relates to train dispatching systems, and moreparticularly to a synchronous selector train dispatching system of thetype whereby communication is established between the centraldispatchers office and each way station successively, for effecting thetransmission of various indication impulses over a j comparatively fewline wires.

Ina synchronous selector type dispatching system, partial circuitsarecompleted-at the dispatchers oifice sequentially and in .;syn-'chronism with other partial circuits at various, way stations connectedin series there- WitllgSO that-indication impulses may be transmitted toalarge number ot traflic controlling devices, and thatindicationimpulses denoting the progress of trains, commonly called, OSindications, may be transmitted to-the dispatchers oiiice. Thesemomentarily i-n'ade circuits may be conveniently called messagechannels,with the time required, to successively complete the total number ofchannels for a. particular system, termed the totaltime cycle.

By Way of illustration, suppose that a dispatching system is'used tocontrol tratfic over asingle tra cl: railroad having'twenty passingsidings. "If these passing sidings wereof considerable length andrequireda separate way station control apparatus at each end of thepass-in'g'siding, then there would be 40 way stations. Assuming that themessage channelsneeded for each way stationto control the-switchmachine'and signals at each way station-and to transmit the OSindication, numbered four messagechannels, then the total number ofmessage-channels for the s-yst-c-nrwouldequal160. Assuming that eachmessage channel requires"one-fifteenth of a second for coinpletion andthe transfer from one Way station to another way stationrequirestwofifteenths-ofa second, then the total time cycle of this specificillustration would equal approximately "sixteen seconds;

'Expe'rience in practice "has-taught, that there is but 'a smallpercentage of the total number of message channels setaside for thetransmissionot control indications which are actually-used for"transmitting control indicationsatany one' time. Thus, if the con-1929. Serial nc. 358,810.

trol indication message channels at a way station,-where controlindications are to be transmitted are set upand all other controlinclicationmessage channels are not set up, then the total time cyclehas been considerably reduced.

ltis of course'u-nderstood' that the OS indications' are very importantand necessarily should be transmitted to the dispatcher as soon aspossible. Thus, the reduction of a total time cycle assists in thisrespect.

In a'certain type of train dispatchingsystem to whichthepresentinventionis particularly'well adaptable only one form of OSindication need be transmitted to the*dispatcher s ofli'ce for each waystation, namely the condition of occupancy of the detector trackcircuit. It is-fu'rther seen that, if a control indication is to betransmitted to a way station at the extremeendof the territory undercontrol of the dispatcher, then as the control is automaticallytransferred from one waystation to the next way station successively,the OS indications may be picked up at each station as the transfer ofcontrol is accomplished, ,thus, the time re-' quired for the OSindication message channels is eliminated, as the time required fortransferring from one way station to the next way station is suflicientfor both the transfer function and for the transmission of an OSindication. I 7

Again. assuming the figures asused in the former illustration, the totaltime cycle now has been greatly reduced as will bepresently shown,assume of course 'that'there are no control indications to betransmitted, the total time cycle of the system for picking up.

all OS indications, or briefly expressed as OS-scan'ning, may be.completed'in approximately six seconds. There'are now only 120 messagechannelsto be set up for control indications, should every "switch andsignal on the system-under control of the system be desired to Shecontrolled simultaneously. However, in practice there would probably notbe more than four or five stations receiv ing controlling indicationsduring anyone total cycle, which has thus been reduced to what might becalled {a minimumvalue able through the use ofproperly designedmechanisms for completing a certain required number of message channels,of which a predetermined number are sequentially set up in each totaltime cycle, and a certain number for each way stationwhich aresequentially setup-for that way station only, when there are indicationimpulses to be sent to that particular way station. These messagechannels are to be used for the transmission of indication impulses forcontrolling the switch machines, signals, de-rails and the like, withinthe territory over which the system has control. In accordance with thepresent invention, it is further proposed totransmit a plurality ofpositive impulses over a transfer circuit including a transfer line wireand common return wire to efiect the transfer of the dispatchers controlfrom one Way station to the next successively, with the control given'toeach successive station after its selecting impulse, and when suchcontrol over each way station has been successively set up, then theoriginal starting position shall be attained by a negative impulse.Also, during such/time that the system is transferring from one waystation to the next way station the OS indication impulses is proposedto be picked up, as each station is successively under control. On theother hand the message channels used for control indication impulsesshall be set up only at such time as a control lever has been moved to anew position effecting a control for that particular way station, withsuch message channels established through the synchronous operation of agroup of channel selecting relays at the .dispatchers office and a groupof channel selecting relays at the way station to which a controlindication impulse is to be transmitted. These groups of relaysoperating synchronously to set up the control indication messagechannels e'f fected by the transmission of a plurality of alternatepositive and negative impulses over a stepping circuit, including thestepping wire and the' common return wire, wi h each impulse energizingone of the above mentioned relays in the dispatchers office and one ofthe above mentioned relays in the way station then under control, duringwhich period of time that exists between the movement of two successiverelays, a message channel between the particular way station and thedispatchers; oflice'is set up.

Other objects, purposes and characteristic features of the presentinvention will in part be obvious from the accompanying drawings and inpart be pointed outas the description progresses.

In describing the invention in detail, ref- .erence will be made to theaccompanying drawings, in which Fig. 1A illustrates conventionally theequipment in the dispatchers ofice of one specific embodiment of thepresent invention;

Fig. 1B illustrates conventionally the e uipment of the first waystation; and, Fig.

lb illustrates conventionally the apparatus at thesecond way station. i'i Description of apparatus In practice dispatching system may be usedto control the switch machines and wayside signals of a large portion ofa railway system, possibly including passing sidings, diverging routes,draw bridges, railroad crossings and the like, however, the presentinvention has forv convenience been shown as applied to the apparatusused for ehecting the control of trahic at the east and west ends of apassing siding PS (see Figs. 1B and 1G). The passingsiding PS isassociated with a main track having track sections TK 'IK and TK of asingle track railway system, provided with absolutepermissive-blocksignaling except at track sections such as TK and TK which are under thecontrol of the dispatcher. The track sections TK and TK containtrackswitches TS and TS respectively, which have associated therewiththe usual detector track circuits. Track section TK including a foulingtrack section FS is inclosed by insulated joints 1 and 2. Likewise thetrack section TK including a fouling track section FS is inclosed byinsulated joints .3 and l. These track sections TK and TK' haVe trackbatteries 5 and 6 respectively, associated therewith, to supply energyto their respective track relays TR and TR The starting signals for themain track and passing siding at the west end of the passing siding PShave been designated SW and SW", respectively, and at the east end ofthe passing siding PS has been designated SE and SE, respectively. Atthe west end of the passing siding PS is the main line signal and thetake siding signal SE and SE", respectively, and at the east end of thepassing siding PS is the main line signal and the take siding signal SWVand SW respectively.

In the dispatchers otfice is preferably located a miniature track layout(see Fig. 1A) corresponding in every detail to the system over which thedispatcher has control. In the particular arrangement shown thisminiature track layout includes the passingsiding p8 and the main linetrack sections 610 ,2570 and 670 This miniature track layout hasindicating lamps I and I associated therewith, which if illuminated,indicate the occupancy of the corresponding track circuits, namely thetrack circuits of track sections TK and TK respectively. The switchmachine SM associated with the track switch TS at the west end of thepassing siding PS is prefma s. a

lever SM- L through the me'dium' of the self.

step-ping synchronous selector system'hereinafter. described. Similarlythe signals SE SE SVV- and SW are'controlledby the signal relay SR andthe direction relay DB which are controlled through the medium of thesynchronous selector-'s';ystem in accordance with the position of leverSL located lnthe dispatchers oiiice. Also, the track switch TSzand thesignalsSE SE, SW and SW arelikewisecontrolled in accordance with theirrespective control leversSML and SL inthe'dispatchers office. The relaysSMR DR -a'nd SR control their respective lunctions ina manner as'fullyset torth in the pendingapplication ofS. N. Wight, Ser. No- 321,185,filed November-22, 1928. V

In the dispatchers oiiice, there are groups of relays completing'thecontrol messagev channels for-the particular way station which aparticular group may represent, one of which groups contain the relaysl2 -and 3 in which the order of the number gives the order of sequentialoperation forthatway stationandthe order "of the exponent gives the.order of that particular way station which-they represent Similarly, thegroup of relays 1 2 and 3 are the control message channel selectingrelays for the second way station, with the reference characters havinga like meaning. The energizing circuits for these groups of messagechannels-selecting relays,are repeated by the line relay 'L while theparticular group to be operated is selected by the master stationselector MST. This master station selector MST includes a plurality ofcircuit selectors M, S and T'mounted upon the same shaft and so arrangedthat a complete cycle of operation is accomplished when the arms of saidcircuit selectors have operated through 180 degrees. The shaft,

upon which the circuit selectors are mounted,

is rotated in 'a clock-wise direction'by suitable motor meanscomprising, an electromagnet'E, an armature A, a lever L, a ratchetfinger R and a sprocket wheel SP. Associated with the lever L are thecontacts 7 and 8. The

- lever L is biased to an upwardposition by a spring 9. The biasingforceof this spring 9 issuilicient to rotate the circuit selectorsM, Sand T one step upon energization and deenergization of the magnet E. Thespring 10 serves to cause the ratchet lever B to always engage sprocketSP.

' The control ofthe stepping impulsegenerating group and associatedrelays is determined by the group selecting relays G and G which arein'turn controlled by the movement of a controljlever effected by the.dispatcher. The stepping impulse generating group of relays is composedof the master relay MR and two time spacerrelaysSand S Also there arethe relays CL, ON and OST-whiclr serve: to control the master stationselecto1 MSil step by step. The relay. RE serves t'OktC'COHIPllSh, the 1reset condition "by producing a negative: impulse ton the transfe'r Iline, while'the' relay ST" starts thesyste-m on its next successivecycleafter the negative impulse lras existed for a suflicient timeto resetthe-system. 'i

Foiupurpose oi-simplification, the points in the circuits" which areconnected to common wire 200' have arrowswith the reference character O.Suitablel'p'ower supply, for thesstep ping impulses is supplied bythebatteries BT and BT connected together-to give positive and negativepotentials "respectively, in resp-ect to the common wire 200. Otherpoints in the circuit whichare connectedto a :power supplyyare shown asconnected 'to indicated sources as (B) and-'('B) 'whichgivepositive :andnegative potentials with respect to said common wire, 200, which :inth'edispatchers-otfice may be batteries BT 0r.-B-T or other separate sourcesLikewise, the indicated sources forthe way stations arese'pa ratebatteries "at each way-station, which: give positive ornegativepotentials with respect to said common wire, and are "maintainedcharged in any suitablemanner, forexample by some trickle charge methoThe dis-patchers office is connected to the way stations-by four-linewires, consisting of HCOIDHIOH' wire 2O0, a transfer wire 201, astepping wire 202, and. a message wire203. The first way station isshown as locatedat the westend of a passing siding PS and is,identicalto lJlIGSGCODd waystation located at the east endo-f the samepassing siding PS. The relays duplicated'in the several Way station'shave like referencecharacters with suitable exponentsdistinguishingthe station to which they belong. Thus, only the first waystation shown inFig. IE will be briefly described. l

The first waystationhas -a transfer relay TltAN of the polarstickf type,which controls the transfer selecting relay TS These relays TRAN and TScompose thetransfer group, determine controlover the message channelselectingrelays A B and O ,-and effect the transferof-control tothenextway station. The energizing circuits of the mes sagechannel'selecting relays is repeated by the line relay L when thetransfer'line has set up communication with this particular Way station.I

It will be'noted'that the OS indicationimpulse is transmitted directlyby thetrackrelays to its respective OS indicating relay which inthis'p'articular embodiment of'the present; invention 1 are relays OSand CS inasmuch as th'esystem is continuously in operation. It isassumed, that where conditions would make it necessary to have OSindications stored, that a'suitable means for storing OS indications maybe usedsuch as 'set forth in pending application of Preston,

the system when notinuse or forrepairs, as the case may be. Itis to beunderstood that should it be desired to have the system normally atrest,.that means for bringing the system to rest after a certain numberof cycles of operation and for again initiating the system whenrequired, may be provided as set forth in our pending application Ser.No. 347,011, filed March 14, 1929, without departing from the presentinvention.

It will be stated here that all polar relays are assumed to have theircontacts moved to a right hand, or positive position, with an application of positive potential to the left hand terminal of the relay,and to be moved to left hand or negative position, with an applicationof negative potential to the left hand terminal thereof. i It is alsoassumed, that the normal position of all relays is their present fullline position, so that when a relay is spoken of as being in a reverseor abnormal position, it shall mean the dotted line position as shown inthe accompanying drawings.

The relays MR, L L and L are of the biased-to-neutral type of polarrelay. In other words their armatures move according to the polarityapplied, due to the permanent magnet incorporated within the relays, butassume a neutral position when deenergized. Other polar relays are thepolar permanent magnet stick type, which respond to an energy impulsefor said polarity by moving its contacts to a certain position asdetermined by that polarity, due to a permanent magnet which isincorporated within the relay. This permanent magnet holds the armaturewhen moved to an extreme position even though the relay is thendeenergized.

The neutral relays incorporated within the circuits of the system arethe usual type and are shown conventionally with heavy base 7 lines insuch cases where they have a slow releasing characteristic.

Lever SML has connected to it by mechanical means the contact 11 whichmoves to a dotted line position when the lever Slvll'i is moved to itsdotted line position. Also, the lever SL has connected to it bymechanical means the contacts 12 and 13, which move to their right handdotted line positions with right hand movement of the lever SL and moveto a left hand dotted line position with corresponding left handmovement of the lever SL Similarly the levers SML and SL have associatedtherewith corresponding contacts 14:, 15 and 16 respectively.

It is believed that the system will be better understood by furtherdescription from the standpoint of operation.

Operation Normally, the system operates to transfer the control of thedispatchers oflice from one way station to the next successiveway sta-vsectionalized by a negative impulse. The system is so organized thatwhen the lever LS is moved to a downward position to stop the system,that the system will always operate up to the positions assumed duringthe time that the re-set negative impulse is placed on the transfer wire201, which in this specific embodiment leaves the relays ON, RE, TS andTS in energized positions.

he relay ON is energized through a circuit traced as follows: frompositive terminal of indicated source having suitable potential, throughfront contact 7, wire 15, relay ON, to the common wire 200.

The energizing circuit for the relay RE is traced as follows: frompositive terminal of indicated source having suitable potential, throughrelay RE, wire 16, reset contact 22 of circuit selector S, through arm17 to the common wire 200.

The relays TS and TS are held energized through similar symmetricalcircuits, with the circuit forrelay TS traced as follows from thepositive terminal of indicated source having suitable potential, throughnegative contact 18 of relay TRAN wire 19, upper windin of relay T S tothe common wire 200.

OS indication soan'ming.lvhen the lever LS is moved to an upward extremeposition to cut in the system, the system operates through a time cycleincluding the scanning of all OS indications, so that the indicatorlight I for station one and representing track section TK indicates theoccupancy or unoccupancy of said track section TK likewise indicatorlamp I associated with track section TK and all other indicator lampsrepresenting other OS-ing track sections are caused to give properindications. This operation which may be called OS scanning, reduces thetimecycle of the system to a minimum value for transmitting said OSindication impulses to the dispatchers office as quickly as possible,and without reducing the facility with which the system can transmitcontrol indication impulses.

Assuming that the lever LS is moved to the upward extreme position,energy is applied to the electro-magnet E causing the ratchet R toretract one step on the sprocket SP thus opening the front contacts 7and 8. The opening of front contact 7 opens the enmenses I .erigizingcircuit for ,thexrel'aytCN, whichin and '21 of the circuitcs'electorsS", T; and M re spectively'move to the 1st step positions.'lhe returnm; of thecontacts i7 'and S te their biased POSlillOIlS closethe energizing circuit fol-the relay Chi, and also the movement oficomes energiz edat the same time that; the

arm 17- ofeircuit selector S movingitmthe 1st step "position, opens thegcircuitfor the re-set relay RE, so that the relay ON berelay RE becomesdeenergizedL Thus'aposis time impulse is pl aced' -uponth'etransferiwire201, .Which: energizes the polar: contacts of: re- TRAN at the first Waystation to" a posi tive' position deenergi'zing the upper coilv of relay"BS Hoivevenas longxas thepositive 7 transfer impulse exists-the relayPS is still held energized through a stickicircuiti including its lowerWinding and front contact.

At this time a circuit is'complet'ed fortransmitting the OS indicationimpulse from the track relay TR tothe OS' indicating relay O8 However,the system: does not remain selected for "the first way' stat-ion, dueto the fact that as soon-asthe relay GN bcecoines'en-c ergized', thecircuit torenergizing the electro-magnet E is ag ain completed providingthat there has-beenno lever movement by the dispatcher. It-is ofcourse'to be understood that the time consumed by' the energization ofthe electro-m'agnet E andthe attraction of the armature A-is suificientto allow thetransmission of the GS indication-impulse-beforethe positivetransfer impulse is broken at "the front contact 8. s

' It is 110W easily seen that'as soon as the front contact 7; is openthe relay GN- isagain deenergized, the circuit forlbh'e ele'ctrmmag 1net; E is broken and the arms 17,20an' d-2-1 of the circuit selectors S,T, and Mmesp'ectivee ly are moved to the 2nd step positions, thusselecting the. second Way station.- as soon as the relayCNagain reachesits energizedlposi-tion Similarly, the other stations of the system areselected successively, H lvIore-specifically, theupward movementof leverLS closes the contact -23 for completing the circuit for theelectro-mtmgnet E and the relay'OST, which is traced as follows :-'t rompositive terminal of indicated source having suitable potential, throughback'contact 24: of relay ST, Wire 25, contact 23; \v-ire 26', startingcontact 270i circuit seiectorT, arm 20, Wire 28, electro-magnet E, Wire-29,- relay 0ST, Wire 30, front contact3li ofrelay-CN, to the commonWireQOO. Y

It. Will be noted here that the relay 0ST is a slow releasing relayhaving such characteristics order thatitdoesnot drop awayd'uringtheinterral bet-Ween transferimpulses of; the normalv rate. Inother Words, the

normal rate of the transfier-impulses supplies sufficient energy tomaintain contact of the relay OST; nthe attracted energizedposi tion,while it the energizingcircuit for relay 0ST is. opened for a timegreater than twice the normal interval; between trans-fen impulses,thenit's contacts assume a deenergized positionf I Also, the closing:of-"front contact 23 of "lever LS ,c closes a circuit throughbackcontact'32'ot relay (DST for permitting the stepping impulserelaygroup composed of: relays MB,:S andilS to operate: I'lowvever,

the contact of: relay 0ST is immediately moved to an energizedpositionsimultaneouslyivvit l1: the' energization of electric-magnet E, sothatithe stepping impulse relay groupdoes I not have time to operatefor. producing more than possibly t'ivoor three-stepping impulses.

This; is not objectionable because it occurs only-at. such ti-met'hatthesystem is started after being under repairs Orin-disuse. Also, thestepping. impulses can; accomplish ,no harm, as thecircuit selectors ofthe master station selecto1".MST are at the reset positionsq vAt thistime theelectro magnet Eris energized;rctfhe'-armature'A isinanwattracted position, resulting in the opening of contacts 7 andRS.The energizing-circuit oftherel-ay UN is'nOWopen at contact 7 V I ThedeenergizationoflrelayCN opens the energizing ,circnit of the electrosmagnet E andithe relay OST at the front" contact 31 of the relay CN.Thearmature- A isrnow released candv the contacts 7 and S a-ssume theirbiased closed positions; Also the circuit selectors -M, S a and T havemoved to the first step position.

With the circuitselectors M, S; and. T in the 1st step position,the-,energizing; circuit forthe' relay RE is broken at the. resetcontact 22 of the circuit selector The res lay ON isfnow-energizedvviththeeontact 7 in its biased position. Thusiit is seen that the relay. REbe'comesdeenergized at the same time;tha-t-.-the relay GN becomesenergized, Which completes acirouitfor placing positive potential uponthe transfer Wire 2'O1,Whic-h is traced as follows :from positiveterminal of indicated source-having sui-table'potential,

through 'frontcontact 38 of relay ON, towire 34, frontcontact 8, Wire35, back contact 36 'otrelay'RE, to thet'ransfer ivireQOl-tothe firstWay station, Wire 37, relay TRAN Wire 38 and 39,10Wernvindingiot relayTS wire 40', from contact 41 of relay TS to the comrmon Wire 200.. Thus,the polar contacts of're-c layTRAN Will move to avpositive position,energizing the upperwinding of relay TS n1 thisconne'ction, attention isdirected to the {act that the deenergization of: magnet iE: re:-

sulting in the movement of arms 21, 1 7 and 20 of circuit selectors M, Sand T respectively, from their zero reset position causes the firstapplication of positive potential to the'transfer wire 201, so thatthefirst way stationtsee Fig. 1B) is selected while the arm 21 assumesthe position lsti.

' The deenergization of relay RE closes a circuit through back contact86 for energizing relay ST, as is obviousfrom the drawing, which has noeffect on the operation of the system until during the last step of thecycle, namely the zero reset position. The positive impulse forenergizing the polar contacts of relay TRAN to a positive position andholding the neutral contacts of the relay TS in an energized position,vcontinues until the armature A attracted by the electro-magnet E, dueto the electro-inagnet E being-en 'ergized through a circuit traced asfollows from positive terminal of indicate-d source having suitablepotential, through back contact 12 of relay G wire43'and 44, firstcontact of circuitselector T,'arm 20, wire 28,

electromagnet E, wire 29, relay OST, wire 30, front contact 31 ofrelayON, to the coin mon wire 200.

At this time the front contact 8 is open discontinuing the positiveimpulse which holds the relay TS energized, thereby effecting droppingof contacts of relay TS and connectin the transfer line 201' to thesecond way station through back contact 15 of relay TS Also theenergizing circuit of relay ON is opened at front contact 7, sothatduring the time that the contacts of relay TS at the first way stationare assuming a deenergizedposition, the contactsof the relay ON are alsoassuming a deenergized position.

As soon as the contacts45 and46 of the relay TS assume their deenergizedpositions the transfer wire 201 and the stepping wire 202 are madecontinuous to'the second way station. The contacts of relay TS? haveplenty of time to assume deenergized positions while the relay ONbecomes deenergized resulting in the deenergization of theelectro-magnet E and producing the movement of the circuit selectors M,Sand T to their second step positions engaging'contacts 2 nd. During thetime that thecircuit selectors M, S and T are inthe 1st step positionsand the relays ON, TRAN and TS are energized with the positivetransferimpulse, a message channel is set up for the transmissionof theOS indication at the first way station. Inasmuch as the track section TKis unoccupied, the track relay TR is energized, so that a negativeimpulse will be placed upon the relay OS through the OS in dicationmessage channel forthe first way station, which is traced as follows:from negative terminal of indicated source having suitable potential,through front contact 47 of relay TR, wire 18, back contact 19 of relayA wire 50, backcontact 51 of relay 13,

wire 52, back contact 53 of relay O Wire 54, front contact 55 of relayTS wire 56, positive contact 57 of relay TRAN wire 58, message wire 203'to the dispatchers ofiice, arm 21 of the circuit selector M, 1st stepcontact of circuit selector M, wire 59, back contact 60 of relay 3 wire61, back contact 62 of relay 2 wire 63, back contact 64 of relay 1 wire65, relay OS to the common Wire 200. This negative impulse'upon therelay oS results in its polar contact remaining in its present negativeposition. Thus the indicator lamp 1 remains unilluminated indicating tothe dispatcherthat the track section TIC is still unoccupied.

With the electro-magnet E deenergized andthecircuit selectors M, S and Tin the 2nd? step positions, the contact 7 is closed completing theenergizing circuit for relay CN, also the front contact 8 completes acircuit for placing positive potential upon the transfer Wire .201 whichresults in the selection of the second way station.

The positiveimpulse for selecting the second way station passes, througha circuit traced as follows:from positive terminal of indicated sourcehaving suitable potential, through front contact 33 of relay ON, wire34, frontcontact ,8, wire 35, back contact 36 of the relay RE, transferwire 201 to the first way station, wire 66, back contact 15 of the relayTS to the second way'station over a transfer wire 201, wire 67, transferrelay TRAN wire 68 and 69, lower winding of relay TS ire 70, frontcontact 71 of relay TS tothe common wire 200. f

Thus the polar contacts of relay TRAN are moved to a positive position,and the neutral contacts of relay TS are held in an energized positionby this same positive transfer impulse.

At this time a message channelis set up for transmitting the OSindication of the second way stationto the dispatchers oflice; As thetrack section TK is unoccupied, a negative impulsewill be applied to therelay OS in the dispatchers ofiice through this message channel which istraced as follows :from negative terminal of indicated source havingsuitablevpotential, through front contact 72 of relay TR wire 73, backcontact 7 4 ofrelay A Wire 75, back contact 76 of relay B wire 77,backcontact 78 of relay C wire 79, front contact 80 ofrelayT wire 81,positive contact 82 of relay TRAN? wire 83, message wire 203 to thedispatchers oflice, arm 21 of the dispatcher that the track. section TKis still unoccupied.

Thus, the system continuesto operate step by step,.0'r in other Words,transfers the control of. the-d spatchers oiiice from one Way station tothen'eXt Way station in a manner It is easily seen that'should either,the track section TK. or thettrackq section Tl? be oc .cupied, that therespective-track relays T3 or IE would be deeneiigized transmitting tothe respective 08- indicating relays positive impulsesinstead ofnegative impulses, which would: result in the illumination of therespect ve lndlcator lamp-l or 1 due to the polar contacts of the relays0S andOS 're-. 1

spectively being in a positive position energizingr its respective,indicator lamp over a circuit. which is obvious from the drawing.

i The-system now operates, until the next to the last step is reached bythe circuit selectors M, Sand ll, atwhiclrtiine the relay CL isenergizedover a circuit traced; as follows fronrposit'ive terminal of"indicated source having suitable potential, thronglrrelay CL, Iii-e91,cont-act 92'of thecircuit'selector SI, contact arm 17,. to the commonwire 200. Thus, the relay CL is energized, and at the sametiineindicjator lamp is ill mine-ted overthe same circuit. Which isapparent from the} drawing.

. The circuit" selectors, takere next step brin 'in i-them-to the-resetiositi'on at'which time the relay REisencrgized througlra 'cir cuitheretofore traced. It's'hould be rememe bered that the'stationarycontact 27 of selector T isnow deener-gizedso that the stepping actionofth'ewmagnet E isdiscontinue'd for the. time beingat least. Theenergizationof relay BE results in the deenergization of relay ST, whichdrops-its neutrallcontact through aslow releasing; period of suilicientextent to allow the negative .in'ipulse, which is placed upon thetran sier Wire,'to reset: or sectionalize the transfer line-201. This neg ativeimpulse is placed uponthe transfer Wire 201: in a manner thati'isobvious from the drawingat the time that the'relay RE is ener gized,andlmovesthe polar contacts of all at the, transfer. relays TRAN andTRAN to a negative positionbefore any-oi theirrespectiverelays T3 and T8reach their ens ergiZed-positions, due to their ener izing circuit beingcompleted'bv thepolar contacts of said transfer relays, this being truehecauseqthe relays TS T etc.. are slower acting than the relaysTRAlNTRAN? etc.

--'A:s,s0on as the relay ST becomes fully .deenergized' the back contact24 completes the-circuit forenergizingthe electro-magnet .E and thesystem again operates through another cycle for scanning the OS indica-vtions. i

' Transmission of control imdioationa-The transmission of acontrolindication impulse does notefi ect the scanning of OS indication"in any manner except after the OS -in dication for the particular Waystation, which is toreceive a control indication has. been transmitted,a pause in'transit'eroccurs,.at Which time the-relayzOST becomes deenergzjized allowing the steppin impulse group of relays comprising relays1R, SFandS to operate; vThe function of these relaysyis to operatethemessage channel selecting relays the di'sp'atche-rs oflicerepresenting-that particular way station. and-themessage chan'e nelselecting relays at that Way station, until these message channelselecting relays have successively completed all the controlindicationimessage channels forthat'way station,

after which thesystem transfers thecontrol to the next Way station andcontinues scan.-

ning the OS indications, until some other statloir 1s selected to WlnchaCOHiLIOl-lIIClICELr tion is to beftransmitted;

As'th-e back contact 93 of relay CL closes the stickfcircuit for thegroup selecting relays G and G the control-,Elevers must be moved atsuch time that this stick circuit is'closed, so that their respectivegroup. relay will remain energized-during {L'COlllPlGtBtOtitl timecycle. It-Will also be seen, thatit is necessary for a lever to bethrow-nimmediately upon the closing 'ofthis stick'circuit, sothat thetransmission ofthe control indication impulse xis insured during thatcycle. If the leverwas thrown durmg the second half ofthe cycle and themessagechannelover Which the control indication impulse should have beentransmitted occurred during thelfirst half of the cycle, then thegroup-selecting relay would become deenergized at the endof the cycleand thecontrol indication impulse would not be transmitted. 1The'indicator 1 is illuminated at the time that the stick circuit forrelays G and G is openechso that if a;lever is moved immediately afterthe momentary illumination of said indicator 1 thestickcircuit will beclosed, and the control indicaion impulse Willbe insured'oftransmission.

f 'By Way of illustration, let'us assume that the dispatcher desires toreverse'the switch machine at theeast end of thepassing sidinc-PS toallowtrafiic to be routed into the passing siding: To do this he movesthe lever SML to the right hand dotted position and in so doing thecontact 14 associatedwith lever SML passes-over-its momentarily madecontact so, that the relay G is energized througlra circuit traced: asfollows :from

positive terminal of indicated source having Cir suitablepotentiahthrough relay Gi'wire 94, wir t 5 and 96, momentarily madecontact 14, to the common wire 200. The relay G is now held energizedthrough a sticlr circuit traced as follows :-from positive terminal ofindicated source having suitable potential, through relay G6, wires 9%and 97, front contact 98, wires 99 and 100, back contact 98 of. relay CLto the common wire 200. The relay G is thus held energized until the relay CL is energizedand opens the back contact 93 which occurs at theendof each cycle.

As the lever SML was moved immediate- 1y after the illumination of theindicator lamp 1", a time interval equal to the reset period occurredbefore the circuit selectors M,'S and T move to the 1st step position.It is assumed, that the master selector MST steps along until the 2ncstep position is reached, at which time the electro-magnet E cannotreceive energy due to the energization of the relay G opening thecircuit of electro-magnet E at the back contact 101 of the-relay G henthis time interval, after the last energization of electronnagnet E andrelay ()ST,has continued for a time equal to twice the normal timeinterval between transfer impulses, then the contact 32 of relay 0STbecomes fully deenergized completing a circuit for allow ing thestepping impulse relay group MR, S S to operate for placingsteppingimpulses upon the stepping wire 202. I I r g If the first impulseproduced by the stepping impulse relay group composed of relays MR, Sand S should be a negative impulse it would be ineffective to producethe energization of any message channel selecting relay. Hence, we willassume that the stepping impulse generating group of relays are in theirpresent full line positions, so that when the back contact 32 is closed,that a circuit is set up for energizing the master relay MR to apositive position.

For the purpose of simplicity only the cir-- cuits will be traced forthe operation of the stepping impulse relay group as its opera- 'tionand function is fully described in pending application of Hitchcock andDicke, Ser. No. 3 -5,607. filed March 9, 1929. This application alsodescribes how the message wire may be connected through the contacts ofthe stepping impulse group so that the messages will be sent over theirmessage channels only during a central interval tr time ofthe totalchannel. time. It is to be understood that the same principle may beapplied to this specific embodiment without departing from the scope ofthe present invention. Also the message channel selecting group ofrelays,such as relays 1 2 and 8 have their operation and function fullydescribed in pending application of O. H. Dicke, Ser. No. 354-,881,filed April 18, 1929, so that it is only necessary to trace the circuitsinvolved. in -the present invention.

108, positive contact 104; 01'' rela Vith the back contact 2 of relayOST i'ully deencrgized, positive energy is placed upon the master relayMRthrough a circuit traced as. follows:from the positive terminal ofbattery 3T through wires 102 and 105, back contact 32 of relay CST, wire106, front contact 28 of lever LS, v.1re 107, master relay MR, .u'ire108 and 109 to the common wire 200. The contact 110 of the iii-asterrelay MR is energized to a positive position placing positive. potentialupon the stepping line operating the contacts of line relays L" and L topositive positions which in turn energized the relays 1 and 11 Thispositive impulse is placed upon the stepping line through circuit tracedas follows: from the positive terminal of batteryBT to wires111,positive contact 110, wire 112, relay S wire 118, relay L throughthe stepping wire to the first way station, through bacl-I contact 16'of relay TS, through the stepping wire 202, to the second way station,thrr .p'h front contact 11 1- of relay TS wire 11o, relay L tothe commonwire 200. Thus the Contact 116 of relay S contact 117 of relay U and thecontact 118 of the relay L are moved to positive positions. V

With the positive contact 117 of relay'L closed a circuit is completedforenergizing the relay 1 which is traced as follows: from positiveterminal of indicated source having suitable potential, through positivecontact 117 of relay 11, wires 119 and 120, back contact 121 of relay 2wires 122'and 123, relay 1 wire 124, had: contact 125 of relay 2 wire126 and 127, back contact 128 of relay 3 wires 129 and 130, secondcontact of circuit selector S, arm 17, to the common wire 200. The'energization of relay 1 closes a' stick circuit through front contact181 as is obvious from the drawing.

At the second way station the relay A is energized through similarsymmetrical circuits as relay 1 due to the fact that the contact 118 ofrelayL is in a positive position. Upon the energization of relays 1 or Aa message channel is completed for energizing S wire the relay SMR whichin turn controls the N switch machine SM for reversing switch TS v V IThis message channel for controlling the switch machine relay SMR forcontrolling the track switch TS traced as follows from positive terminalof indicated source having suitable potential, through lever SML in aright hand position, through wire 132, front contact 89 of relay 1 wire88, back contact 87 of relay 2 wire 86, back contac 85 of relay 3 wire84, 2nd step contact of circuit selector M, arm 21, through the messagewire 203 to the second way station, wire 83, positive contact 82 ofrelay THAI wire 81, front contact 80 of relay TS wire 70.

track contacts of relays 2 and B back contact 78 of relay C wire 77,back 0011- a positive position the contact 10101 relays is energized toZL HQ 'QfiVG POSItlOIl through a circuit traced as follows :from thenegative terminal of battery BTZ through wires 13% and 135, positivecon-ta ct 116 of relay S wire 13 6, relay S wire 137 and 109 to thecommon wire 200. Thus the polar Contact 104 of re lay S is moved to anegative position placing a negative potential upon the relay MR,throiiigh a circuit traced as follows :tro1n the negative terminal ofbattery BT wires 13 i'a'nd 138, negative contact 10 1 of relay 8", wires 105,:back contact 82 of relay 0ST, wire 106 front contact 23 oflever LS, wire 107, relay MR, wire 108 and 109, to the common wire 200.Thus, the Contact 110 ofthe relay MB is energized to a negative positionplacing negative potential upon the relays S 11 and L from the negativeterminal of battery BT through Wire 139, negative contact 110, through acircuit heretofore traced for energizing the relaysS L and L Thecontact-116 of relay S is moved to anegative position, thus causing thecontact 104 ofrelay S to be moved to a positive position, resulting inthe energization of the master relay MR with a positive impulse'whichoccurs in due time. p

In the mean time with the contacts of the line relays in anegativeposition the relays 2 andB are energized and the stick circuits of therelays 1 and A? are opened by back The relay 2 is energize-d through acircuit traced as follows :from positive terminal of indicated sourcehaving suitable potential negative contact 117 of relay L", wire 140 and1 11, front contact 142, wires 143 and 14 1, relay 2 wires 1 1 5 and127, back contact 128, wires 129 and 130, 2nd step contactof circuitselector S, arm 17, to the commonwire 200. The relay B is energized withcontact 118 of relay L in a negative position through a similar circuit.The relay 2 is held energized through a stick circuit including frontcontact 1 16. I c

The next impulse placed upon the stepping line by the stepping impulsegenerating relay group is a positive one and energizes the co ntacts ofrelays S L and L to a positive position. 1th the contact 117 of relay Lin a positive position the relay 3 is energized 11116147 and 14s, relay3 wires 149 and 130,

of the ,2nd step contact offselector S, arm 17 to the common wire 200.The relay3 'is held "energized'through a stick circuit including-frontcontact 150 unt'ilthe stick cir. cult s open by the movement of selectorarm 17 to the 3rd step position. The relay C isenergi'zed throughsimilar circuits simultaneously wlth relay 3 Upon theenergizationoirelay 8 a circuit is completed for energizing the electro mag net andrelay 0ST, which is traced as follows trom the positive terminal ofindicated source having suitable potential through front contact 151 ofrelay 3 wire 152 and 153, 2nd step contact of circuit selector T, .arm20, wire 28,electro-1nagnet E, wire 29, relay OST, wire 30,front'contact 31 oi relay UN, to the common wire 200. The electro-magnetE and relay OST are thus energized. The steppingimpulses are thusdiscontinued by the attraction of back contact 32 of relay (1ST. Also.the circuit selectors M, S and T are moved to the 3rd step position assoon as therelay UN becomes deenergized allowing the armature A to bereleased. The stick circuit for the relay 3 is now opened at the 2ndstep contact of cir cuit selector S, also the third way station has beenselected, so that the relay TS of the second way station has beendeenergized and the stick circuit of the relay C has been opened at thefront Contact 151 of the relay T8 V The master circuit selector MSTproceeds to select further way station as herebefore described. .Atthenext to the last step the relay CL is energized and the stick circuittorthe relay G is opened at the back contact 93. Aydescrip'tion of thetransmission or" a 0 control indication impulse has thus been given andin a smilar manner all other control impulses are transmitted accordingto the movement of any particular control lever.

It is noted'tha-t the regular OS-scanning is interrupted vfor thetransmission of a control impulse only at the time that the station isselected to which the control impulse is to be transmitted. Thus, thetotal time cycle ofthe system is notmaterially increased by thetransmission of a comparatively large number of control indicationimpulses,

Themanner in which the system is organized in order to accomplishautomatic reverse position, the lever SL must be moved toa lefthandposition, which causes a negative impulse to be placed uponthedirection] are controlled in accordance with the position of theswitch machine SM and the relays D3 and SR is completely set forth inthe application by S. N. Wight, Ser. No.

821,185, filed November 22, 1928. Similarly,

the movement of lever SML to a right hand position reverses the trackswitch TS by sending a negative impulse tothe relay Shlll overitsrespective message channel. J Also lover SL moved to a left handposition, transmits a negative impulse to the direction relay DB and apositive impulse to the signal relay SR over their respective messagechannels. It must be remembered that in every case where a levermovement is made that it must be done immediately after the illuminationof indicator lamp 1, so that the stick circuit for the group selectingrelay representing that particular station may be completed. In thisconnection, if desired the group selecting relay, such as G may be stuckup for two cycles of operation in a manner taught in the application ofHitchcock and Dicks, Ser. No. 845,667 above referred to. Assuming thatthe levers SL SML and SL have been moved to left hand positions so thata train may be routed over the passing siding, the message channels forthe respective control relays will be traced. It will also be assumedthat the system steps along in a manner as heretofore described andhesitates at their respective steps and at proper times as heretoforedescribed.

The message channel for the relay BB is tracec as follows: from negativeterminal of indicated source having suitable potential, through lever SLin a left hand position, wire 152, front contact 87 of relay 2 wire 86,back contact 85, of relay 3?, wire 8%, second step contact of selectorM, arm 21, through the message wire 203 to the second way station, wire83, positive contact 82 of relay TBA wire 81, front contact or re- TSwire 79, back contact 78 of relay 0 wire 77, relay DE to the common wire200.

The message channel for the signal relay SR is traced as follows :-frompositive terminal of indicated source having suitable potential, throughcontact 15 in a left hand po sition, wire 15 1, front contact of relay 3wire 8-1, second step contact of circuit selectorM, arm 21 through themessage wire 203 to the second way station, wire 83, positive contact 82of relay Tltilll wire-81, front contact 80 of relay T53 wire 79, frontcon- SR to the front contact 76 of relay B wire 15.3,

chine relay Sll lll is traced as follows :from g terminal of indicatedsource having table potential, through le'verSML in a right handposition, wire 156, front contact 6-1 of relay 1, wire $8, bacl: contact'62 of relay 2 wire 61, baclrcontact 60 of relay 3 wire 50, first stepcontact of circuit selector M, arm 21, through the message wire 203, tothe first way station, wire 58, positive contact of relay TRAN wire 56,front cont ct 55 of relay TS wire 54, ba k contact 53 of relay C wireSQ,back contact 51 of relay B wire 50, front contact 49 of relay A wire157, rolay SMPG, tothe common wire 200.

The message channel. for the relay DB is traced as follows :-fromnegative terminal f indicated source having suitable potential, throughlever SL in the left hand position, wire 158, front contact 62 of relay2 wire 61, back contact 60 of relay 3 wire 59, first step contact ofcircuit selector M, arm 21, through the message wire 203 to the firstway station, wire 58, positive contact 57 of relay TRAN re 56, frontcontact 55 ofrelay TS wire 5 baclr contact 53 of relay C wire 52, frontcor act 51 of relay B wire 159 of relay DB to common wire 200.

The message channel for the relay SR is raced as follows from thepositive termial of indicated source having suitable pocntial, throughcontact 12 in a left hand osition, wire 160, front contact 60 of relaywire 59, first step contact of circuit selecor M, arm 21, through themessage wire 203 L0 the first way station, wire 58, positive contact 57of relay TRAN", wire 56, front contact 55 of relay TS, wire 54, frontcontact 53 of relay C wire 161, relay SR to the common wire 200.

n ative It is noted that the total time cycle of the system embodyingthe present invention is variable from a minimum value, including thescanning of all OS indications, to a maxi mum value including thescanning of all OS indications plus the transmission of all controlindication impulses. However, as the number of control indicationimpulses are comparatively few for any one total time cycle, then thetotal time cycle is usually of a value near the minimum.

@ The automatic picking of OS indications during the transfer operationfrom station to station, is peculiarly adaptable to dispatching systemswhere there is but one OS indication to be picked up at each way stationand where there are several tral'lic controlling devices at that waystation to be controlled. Also, tiis specific embodiment inherentlycauses the isolation of all message channels so that any short circuitor defect at a particular message channel does not effect messagechannels of other way stations.

rr-semi invention-is involved in the complete syn' chronization ofthewholesystem at the end of each total time ,cycle.;;-

- Having thus shown and described one specific embodiment of a 'rathermvolyedand comprehensive. system for carrying out cer' tain functions,it is desiredto be understood that theparticu'lar arrangement of devicesand circuits illustrated, need not be'adhered to, but that many changes,modifications and additions may be made, in the individual device aswell as in their coordination with each other, without departing fromthe scope or spirit of the invention, except as demanded by the scope ofthe appended claims.

What we claim is 1. In a train dispatching system of synchronousselector wayside signal control type, the combination with a dispatchersoffice and a plurality of way stations along the railway track, of amaster synchronous selector at the dispatchers office, a waysidesynchronousselector distributed along the railway track, steppingmeansfor operating said synchronous selectors in synchronism to successivelycomplete alarge number of message circuits, there being only one OS- ingmessagecircuit and atleast one control message circuit'for eachwaystation, said stepping means including means for at times, setting upsuccessively sa1d OS-ing message circuit only and at other times settingup said QS-inginessage circuits and sa1d control message clrcuitssequentially.

2. In a train-dispatching system of the synchronous selector'waysidesignal control type, the combination with a dispatchers office andplurality of way stations along the'railway track, of a mastersynchronous selector at the dispatchers ofiice,-a wayside synchronousselector distributed along'the railway track, stepping means foroperating said synchronous selectors in synchronism tosuccessivelycomplete a large number of message c1rcu1ts,'there-beingonly one OS-ing message circuit and at least one control message circuitfor each way station, said stepping means including means for at timessetting up successively said OS-ing message circuit only and at othertimes setting up said OS-ing message circuits andsaid con:

trol message circuits sequentially.

3. In" a train dispatching system'ot the synchronous selector waysidesignal control type, the combination with a dispatchers offree and aplurality of way stations along the railway tracln of a mastersynchronous select'or at the dispatchers ofice, a wayside synchronousselector distributed along, the

railway track, stepping means for operating said synchronous selectorsin synchronism to successively complete a large number. of messagecircuits, therebeing only one @S-ing message circuit and at least onecontrol mes sage circuit for each way station,lsaid stepthe"- ping'meansincluding means forat times hurdling some of'said controlcircuits butnot hurdling any of said' OS-ing message circuits;

selector train dispatchl. A synchronous ing system comprising, acombined way station selecting and 08 message circuit closingsynchronousselector located at the dispatchers ofiice,.a sim larcombined way station selector and OS -message circuit closingsynchronous selector distributed along the track with portions thereofat each of a plurality of way stations, supplemental home synchronousselectors one for each way station at the dispat'chers oiiice, asupplemental way sta-' tion synchronous selector at each way station,means for operating the two mentioned Way station selecting andOSmessage circuit clos ing synchronous selectors in synchronism tosuccessively'select all of said OS message circuits and including meansfor at times hesitating when aparticular way station isselected andeffecting the operation of the supplemental synchronous selectors forsuch particular way station to close a particular control,messagecircuit, and wayside signals cont-rolled over said control messagecircuits.

5:A synchronous selector tr in dispatching system comprising, a combinedway station selecting and OS message circuit closing synchronousselector located at the dispatchers office, a similar combined waystation selectorand OS message circuit closing syn chronous selectordistributed along the track with :portionsthereot at'each of aplurality'ot way stations, supplemental home synchronous selectors onefor each waystation at the dispatcherscofiice, a supplemental waystation synchronous selector at each Way station,.means for operatingthe two mentioned Way station selecting and OS message circuit closingsynchronous selectors in synchronisin to successivelyselect all ofsaid'OS message circuits and including means for at-times hesitatingwhen a particular way station is selected a'nd effecting theop'eration'of the supplemental synchronous selectors for such particular Waystation to close successively all of the control message circuits atsuch way station, aiidwvayside signals controlled over said controlmessage circuits.

6. Ina train dispatching system of the synchronous selector type; thecombination with a dispatchers office and a plurality ofelectro-magnetincluding contacts closed only 1n the last preceding stepof said home selector, means for opening such circuit when saidelectroanagnet has been completely. retract-' ed, whereby said homeselector is operated step by step until it reaches a position where thecircuit "for sale electro-magnet is not reclosed; way sta ionsynchronous selector including a plura -ty of sequentially operatedrelays o rated step by step in synchronism with said hom synchronousselector; a plurality of message circuitsinclnding contacts or" saidhome selector and said way station selector, and wayside signalscontrolled over said message circuits.

7. In a train dispatching system of the synchronous selector type; thecombination with a dispatchers office and a plurality of way stationsalong the rallway track; or" a home synchronous selector comprising, arotary shaft having a plurality of contact arms for engaging stationarycontacts and connected to a ratchet wheel, a spring operated pawl foroperating said ratchet wheel one step at a time, an electromagnet forretracting said pawl and reloading said. spring, a circuit for each stepof operation for said electro-magnet including contacts closed only inthe last preceding step of said home selector, means for opening suchcircuit when said electrotors so that said home synchronous selector isheld at rest until the contact of said supplemental synchronous selectoris closed.

8. In a train dispatching system of "the synchronous selector type, thecombination with a dispatchers otfice and a plurality of way stationsalong the railway track; of a home synchronous selector comprising, arotary shai't having a plurality of contact arms for engaging stationarycontacts and connected to a ratchet wheel, a spring operated pawl foroperating said ratchet wheel one step at a time, an electro-magnet forretracting said pawl and reloading saio spring, acircuit for each stepof operation for said electro-ma 'net includin contacts closed onl inthe last preceding step of said home selector, means for opening suchcircuit when said electro-magnet has been completely retracted, wherebysaid home selector is operated step by step until it reaches a positionwhere the circuit for said electro-magnet is not reclosed; a way stationsynchronous selector including a plurality of sequential'y operatedrelays operated step by step in synchro nism with said home synchronousselector; a plurality of messagecircuits including contacts of said homeselector and contacts of said way station selector, waysid signalscontrolled over said message circuits, supplemental synchronous selectoroperable over the same line circuits, and means for at times arrying thecircuit for said electrosmagnet through a contact of one oi saidsupplemental synchronous selectors so that said home synchronousselector is held at rest until the contact of said supplementalsynchronous selector is closed.

9. in a train dispatching system of the synchronous selector type; thecombination with a dispatchers otfice and a plurality of way stationsalong the railway track; of a home synchronous selector comprising, arohaving a contact arm for engagionary contacts and connected to aratchet wheel, a spring operated pawl for operating said ratchet wheelone step at a time, an electro-magnet for retracting said pawl and"reloading said spring, a circuit for each. step of operation for saidelectro-magnet including contacts closed only in the last preceding stepof said home selector,'means for opening such circuit when saidelectromagnet has been completely retracted, whereby said home selectoris operated step by step until it reaches a position where the circuitfor said selector is not reclosed; another synchronous selector operatedin synchronism with said home synchronous selector selecting a difierentway station for each step of said home synchronous selector, asupplemental synchronous selector at said dispatchers office and at eachof said way stations, and means for causing said home and said anothersynchronous selectors to hesitate when a particular way station isselected for permitting the corresponding supplemental synchronousselector to complete its operating cycle, I

10. In a train dispatching system of the synchronous selector type; thecombination with a dispatchers oflice and a plurality of way stationsalong the railway track; of home synchronous selector comprising, arotary shaft having a contact arm for engaging stationary contacts andconnected to a ratchet wheel. a spring operated pawl for operating saidratchet wheel one step at a; time, an electro-magnet for retracting saidpawl and reloading said spring, a circuit for each step of operation forsaid electro-magnet including contacts closed only in the lastprecedingstep of said home selector, means for opening such circuit whensaid electromagnet has been entirely retracted, whereby said homeselector is operated step by step until it reaches a position where thecircuit for said electro-magnet is not reclosed; a stick relay, a levercontrolling a distant tralilc controlling device through the mediumot'said home synchronous selector, a pick-up circuit ior said stickrelay closed momentarily upon movement of said lever tromone to anotheroi' its operated positions, a stick circuit tor said relay brokenmomentarily when the synchronous selector has completed a particularoperating cycle, a' back contact on said stick relay included in theenergi: circuit for said electro-magnet when said home synchronousselector assumes a particular step, thereby causing said homesynchronousselector to stop when it reaches that particular step; a supplementalsynchronous selector initiated it the home synchronous selectorhesitates at that particular step for more than'a predetermined periodof time; and a contact con nected in multiple withsaid back contact forsaid electro-magnet including contacts closed only in the lastprecedingstep of said home selector, means for opening such circuit when saidelectro-magnet has been completely retracted, whereby said home selectoris operated-step by'step'until it reaches a position where the circuitfor said electromagnet is not reclosed; a stick relay, a levercontrolling a distant trailic controlling device through the medium ofsaid home synchronous selector, a pick-up circuit for said stick relayclosed momentarily upon movement of 'sald lever i'rom one to another of"its operated positions, a stick circuit for said stick relay brokenmomentarily when the synchronous selector has completed a particularoperating cycle, a back contact on said relay included in the energizingcircuit for said electro-magnet when said home synchronous selectorassumes a particular step,

thereby causing said home synchronous selector to stop whenit reachesthat particular step; a supplemental synchronous selector initiated ifthe" home synchronous selector hesitates at that particular step formore than a predetermined period of time; and a contact connected inmultiple with said back contact and closed onlywhensaid supplementalsynchronous selector has completed its cycle of operation,

12. A method of train dispatching including the control of switchmachines and signalsfrom a dispatchers offiee and the indication ofdistant track circuit occupancyin said dispatcherls oifice through themedium ofsynchronous selectors, wh-1ch cons sts 1n normallySCZLIlIllIlg-flll indicating message circuits sequentially in rapidsuccessionof a" synchronous selector system; andinat othertimeshesitatlngat a particular ndicating message circuit and durmg suchhesitation scanning a plurality of control message cir cuits in rapidsuccession.

13. A method of train dispatching includingthe control of switchmachines and sig-@ nals from a dispatche1"s ofiice-and the indication inthedispatchers ofi ice of track circuit occupancy 01" distant trackcircu ts through the medium of synchronous selector ,i whi'ch consistsin normally successively selecting in rapid sequence all of the waystations of the system and in simultaneously therewith scanning theindicating message circuits therebeing only one indicating'mes sagecircuit for each way station,and in at other times hesitating at aparticular way stationandfduring such hesitation in first scanning theindicating message circuit at that way station inthen scanning aplurality of control message circuits for said way station. v, i

14. In a centralized traflic controlling sys-' tem for railroads, thecombination with a central "office and plurality of way stations, a

track circuitat each of said way stations, signals at each o fsaid' waystations, and selector apparatus at said central oilice and at each 0tsaid plurality of way stations effect1veto normally successlvelyindicate the condltlon "of occupancy of said track circuits andincluding means to cause said apparatus to hesitatewhenthecondition ofoccupancy ofa I particulartrac'k circuit is indicated in the.

event a signal is to be controlled fromcsaid centraloflice to permitother selector appara tus to control such signal, and line circuitsconnecting saidselector apparatuses.

Ina centralized tral'lic controlling sy si 'tem' for railroads, thecombination with a central oilice and a-plurality of-way stations, atrack circuit at each of said way stations, signals at each ot'said waystations,and selector apparatus atsaid central ofiice and at each ofsaid plurality of way stations effective tov normally successivelyindicate the condition of occupancyof, saidtrack circuits and including.means to cause said apparatus to hesitate when the condition ofoccupancy of a particular trackcircuit is indicated in the event asignal is to be controlled from said central office to permit otherselector apparatus in combination with said first. mentioned selectorapparatus to control such signal,

and line circuits connecting said selector apparatuses.

16. In a centralized traffic controlling sys- Iva temfor railroads,thecombination with a central ofiic'e and aplurality of way stations, atrack circuit at each of said way stations; signals at each of said waystations, and selector apparatus at said central office and at each ofsaid pluralityof way stations effective to normally successivelyindicate the condition of occupancy of said track circuits and includingmeans to cause said apparatus to hesltate When the condition ofoccupancy of a particulartrack circuit is indicated in the event asignal is to be controlled from said'central officeto permit otherselector apparatus to control such signal over the same line circuitover which said first mentioned selector apparatus indicates theoccupancy of said track circuits.

17. In a centralized trafiic controlling system for railroads; thecombination with line wires connecting a central oflice and a pluralityof way stations; a track circuit at each way station; selector apparatusfor successively indicating the occupancy of said track circuits; a'si'nal associated with each track circuit; a lever in the central ofiicefor. each signal; separate selector means at the central ofi ice and ateach way station for controlling the signal at such way station; andmeans for causing said first mentioned selector apparatus to stop, whenthe track circuit occu-. pancy at a particular way station is being in--dicated to allow said other selector apparatus to control the associatedsignal over a line wire used by said first mentioned selector when thelever for said signal has been Jlaced out of corres ondence with such sinal, long enough to allow such signal to be '7 controlled .v

18. In a centralized'traflic controlling system for railroads, thecombination with a central ofrice and a plurality of way stations atpassing sidings along the railway track, selector apparatus at saidcentral oiiice and at each of said way stations to afford communicationbetween said central ofiice and each of said way stations byestablishing such com munication with each way station successively onceduring each cycle of operation of sand selector apparatus, and anindicator in said central office for indicating when such cycle has beencompleted.

In testimony whereof we aflix our signatures. 1

OSCAR H. DIGKE. NEIL D. PRESTON.

DISCLAIM ER 1,794,591.Oscar H. Blake and Neil D..P?"est0n, Rochester, N.Y. TRAIN-DIS- PATCHING SYsTEM ron RAILROADS. Patent dated March 3, 1931.Disclaimer filed February 16, 193 1, by the assignee, General RailwaySignal Company.

Hereby enters this disclaimer to claims 1, 2, 3, 12, 13, and 18 of saidLetters Patent, which are in the following words, to witz- 1. In a traindispatching system of the synchronous selector wayside signal controltype, the combination with a dispatchers ofiice and a plurality of waystations along the railway track, of a master synchronous selector atthe dispatchers oflice, a wayside synchronous selector distributed alongthe railway track, stepping means for operating said synchronousselectors in synchronism to successively complete a large number ofmessage circuits, there being only one OS-ing message circuit and atleast one control message circuit for each way station, said steppingmeans including means for at times setting up successively said OS-ingmessage circuit only and at other times setting up said OS-ing messagecircuits and said control message circuits sequentially.

2. In a train dispatching system of the synchronous selector waysidesignal control type, the combination with a dispatchers ofiice and aplurality of way stations along the railway track, of a mastersynchronous selector at the dispatchers oflice, a wayside synchronousselector distributed along the railway track, stepping means foroperating said synchronous selectors in synchronism to successivelycomplete a large number of message circuits, there being only one OS-ingmessage circuit and at least one control message circuit for each. waystation, said stepping means including means for at times setting upsuccessively said OS-ing message circuit only and at other times settingup said OS-ing message circuits and said control message circuitssequentially.

3. In a train dispatching system of the synchronous selector waysidesignal control type, the combination with a dispatchers ofiice and aplurality of way stations along the railway track, of a mastersynchronous selector at the dispatchers oflice, a wayside synchronousselector distributed along the railway track, stepping means foroperating said synchronous selectors in synchronism to successivelycomplete a large number of message circuits, there being only one OS-ingmessage circuit and at least one control message circuit for each waystation, said stepping means including means for at times hurdling someof said control circuits but not hurdling any of said OS-ing messagecircuits.

12. A method of train dispatching including the control of switchmachines and signals from a dispatchers office and the indication ofdistant track circuit occupancy in said 'dispatchers oflice through themedium of synchronous selectors, which consists in normally scanning allindicating message circuits sequentially in rapid succession of asynchronous selector system; and in at other times hesitating at aparticular indicating message circuit and during such hesitationscanning a plurality of control message circuits in rapid succession.

13. A method of train dispatching including the control of switchmachines and signals from a dispatchers ohice and the indication in thedispatchers ofiice of track circuit occupancy of distant track circuitsthrough the medium of synchronous selectors, which consists in normallysuccessively selecting in rapid sequence all of the way stations of thesystem and in simultaneously therewith scanning the indicating messagecircuits there being only one indicating message circuit for each waystation, and in at other times hesitating at aparticular way station andduring such hesitation in first scanning the indicating message circuitat that way station in then scanning a plurality of control messagecircuits for said way station.

18. In a centralized traffic controlling system for railroads, thecombination with a central office and a plurality of way stations atpassing sidings along the railway track, selector apparatus at saidcentral oflice and at each of said way stations to afford communicationbetween said central oflice and each of said way stations byestablishing such communication with each way station successively onceduring each cycle of operation of said selector apparatus, and anindicator in said central office for indicating when such cycle has beencompleted.

[Ojfict'al Gazette March 18, 1984.]

